Abstract: Capacitance-voltage measurements and deep level transient Fourier spectroscopy are used to examine the depth resolved electrical characteristics of Si-doped GaAs/(In,Ga)P/GaAs heterojunctions grown by metal-organic-vapor- phase epitaxy. The depth profiles of the carrier concentration are compared with calculations based on self-consistent solutions of the Poisson equation. It is shown that the depth profiles of GaAs/(In,Ga)P interfaces depend strongly on the growth conditions. For interfaces with disordered (In,Ga)P, the conduction band offset is determined to be 0.20 eV. The estimated carrier deficits at the various heterointerfaces are within the range 1012 - < 1011 cm-2. The apparent loss of carriers at the typical interface is related to the interfacial levels.